/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.graphics;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;

/**
 * PurgeableBitmap demonstrates the effects of setting Bitmaps as being
 * purgeable.
 * 
 * In the NonPurgeable case, an encoded bitstream is decoded to a different
 * Bitmap over and over again up to 200 times until out-of-memory occurs. In
 * contrast, the Purgeable case shows that the system can complete decoding the
 * encoded bitstream 200 times without hitting the out-of-memory case.
 */
public class PurgeableBitmap extends GraphicsActivity {

	private PurgeableBitmapView mView;
	private final RefreshHandler mRedrawHandler = new RefreshHandler();

	class RefreshHandler extends Handler {

		@Override
		public void handleMessage(Message msg) {
			int index = mView.update(this);
			if (index > 0) {
				showAlertDialog(getDialogMessage(true, index));
			} else if (index < 0) {
				mView.invalidate();
				showAlertDialog(getDialogMessage(false, -index));
			} else {
				mView.invalidate();
			}
		}

		public void sleep(long delayMillis) {
			this.removeMessages(0);
			sendMessageDelayed(obtainMessage(0), delayMillis);
		}
	}

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		mView = new PurgeableBitmapView(this, detectIfPurgeableRequest());
		mRedrawHandler.sleep(0);
		setContentView(mView);
	}

	private boolean detectIfPurgeableRequest() {
		PackageManager pm = getPackageManager();
		CharSequence labelSeq = null;
		try {
			ActivityInfo info = pm.getActivityInfo(this.getComponentName(),
					PackageManager.GET_META_DATA);
			labelSeq = info.loadLabel(pm);
		} catch (NameNotFoundException e) {
			e.printStackTrace();
			return false;
		}

		String[] components = labelSeq.toString().split("/");
		if (components[components.length - 1].equals("Purgeable")) {
			return true;
		} else {
			return false;
		}
	}

	private String getDialogMessage(boolean isOutOfMemory, int index) {
		StringBuilder sb = new StringBuilder();
		if (isOutOfMemory) {
			sb.append("Out of memery occurs when the ");
			sb.append(index);
			sb.append("th Bitmap is decoded.");
		} else {
			sb.append("Complete decoding ").append(index)
					.append(" bitmaps without running out of memory.");
		}
		return sb.toString();
	}

	private void showAlertDialog(String message) {
		AlertDialog.Builder builder = new AlertDialog.Builder(this);
		builder.setMessage(message)
				.setCancelable(false)
				.setPositiveButton("Yes",
						new DialogInterface.OnClickListener() {
							public void onClick(DialogInterface dialog, int id) {
							}
						});
		AlertDialog alert = builder.create();
		alert.show();
	}

}
